Report on the flight performance of the Z-93 white paint used in the SERT 2 thermal control system

Evaluating flight performance of Z-93 white paint in SERT 2 spacecraft thermal control system by changes in paint absorptanc

Low-thrust vehicle concept studies

Part of NASA's orbit transfer vehicle propulsion program is devoted to the development of analytical tools to define propulsion system performance, weight, size, and other parameters, and to develop packing concepts for LSS mission propulsion and payload systems. Packing studies discussed relate to shuttle cargo bay constraints; low thrust engine profile and performance; large space frame concept and weight; low thrust vehicles stowed in shuttle, LSS payload capability, and weight distribution. Further study is needed to determine interactions among propulsion system, payload structures, and shuttle. Low thrust-to-weight ratios are desirable to maximize payload weights and deployed areas

Investigation of afterburner combustion screech and methods of its control at high combustor pressure levels

Control of high pressure combustion screech in afterburne

Weight-related teasing in the school environment: associations with psychosocial health and weight control practices among adolescent boys and girls

Weight-related teasing has been found to be associated with low self-esteem, depressive symptoms, body dissatisfaction, and weight control behaviors in adolescents. While research has typically examined weight-related teasing directed towards the individual, little is known about weight-related teasing at the school level. This study aimed to determine the association between the school-level prevalence of weight-related teasing and psychosocial factors, body dissatisfaction and weight control behaviors in adolescents. Adolescents (N = 2,793; 53.2 % female) attending 20 US public middle and high schools were surveyed as part of the Eating and Activity in Teens (EAT) 2010 study. Generalized estimating equations were used to estimate the association between school-level weight-related teasing and health variables, controlling for individual-level weight-related teasing, clustering of individuals within schools, and relevant covariates. A greater school-level prevalence of weight-related teasing was associated with lower self-esteem and greater body fat dissatisfaction in girls, and greater depressive symptoms in boys, over and above individual-level weight-related teasing.Dieting was associated with the school-level prevalence of weight-related teasing in analysis adjusted for covariates in girls, but not following adjustment for individual-level weight-related teasing. Unhealthy weight control behaviors, extreme weight control behaviors, and muscle-enhancing behaviors were not associated with the school-level prevalence of weight-related teasing in girls or boys. Findings from the current study, in conjunction with previous findings showing associations between weight-related teasing, psychological concerns, and weight control behaviors, highlight the importance of implementing strategies to decrease weight-related teasing in schools

A meta-analytic review of stand-alone interventions to improve body image

Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

‘Wellness’ lifts us above the Food Chaos’: a narrative exploration of the experiences and conceptualisations of Orthorexia Nervosa through online social media forums

The increasing prevalence of eating disorders has motivated a burgeoning of research from narrative methods to illuminate the cultural and social aspects of disordered eating habits. A seemingly new eating disorder, Orthorexia Nervosa, has gained visibility through the internet sphere and popular media, though scholarly attention has been scarce. This study develops qualitative understandings of the fixation with ‘clean eating’ through narrative inquiry by employing an internet ethnographic approach. Data were analysed using a thematic narrative analysis, focusing on parallels and divergences across narratives presented online. This article presents 30 male and female voices, illustrating how these individuals understand their eating habits through narratives of pursuit, resistance and recovery, which are largely motivated by the desire for physical, emotional and social change. Crucially, this study illuminates a range of cultural elements enabling eating disorders in response to the transmission of cultural values online set within the broader context and processes of reflexive-modernisation

Judging the difference between attractiveness and health: does exposure to model images influence the judgments made by men and women?

Recent research has shown facial adiposity (apparent weight in the face) to be a significant predictor of both attractiveness and health, thus making it an important determinant of mate selection. Studies looking at the relationship between attractiveness and health have shown that individuals differentiate between the two by preferring a lower weight for attractiveness than for health in female faces. However, these studies have either been correlational studies, or have investigated weight perceived from only the face. These differences have been discussed with regard to sociocultural factors such as pressure from parents, peers and also media, which has been seen to have the highest influence. While exposure to media images has been shown to influence women’s own body image, no study has yet directly tested the influence of these factors on people’s preferred weight in other women’s bodies. Here we examine how a short exposure to images of models influences men’s and women’s judgments of the most healthy looking and attractive BMI in Malaysian Chinese women’s bodies by comparing differences in preferences (for attractiveness and health) between groups exposed to images of models of varying attractiveness and body weight. Results indicated that participants preferred a lower weight for attractiveness than for health. Further, women’s but not men’s preferred BMI for attractiveness, but not health, was influenced by the type of media images to which they were exposed, suggesting that short term exposure to model images affect women’s perceptions of attractiveness but not health

Dissonance-Based Interventions for the Prevention of Eating Disorders: Using Persuasion Principles to Promote Health

The limited efficacy of prior eating disorder (ED) prevention programs led to the development of dissonance-based interventions (DBI) that utilize dissonance-based persuasion principles from social psychology. Although DBIs have been used to change other attitudes and behaviors, only recently have they been applied to ED prevention. This article reviews the theoretical rationale and empirical support for this type of prevention program. Relative to assessment-only controls, DBIs have produced greater reductions in ED risk factors, ED symptoms, future risk for onset of threshold or subthreshold EDs, future risk for obesity onset, and mental health utilization, with some effects persisting through 3-year follow-up. DBIs have also produced significantly stronger effects than alternative interventions for many of these outcomes, though these effects typically fade more quickly. A meta-analysis indicated that the average effects for DBIs were significantly stronger than those for non-DBI ED prevention programs that have been evaluated. DBIs have produced effects when delivered to high-risk samples and unselected samples, as well as in efficacy and effectiveness trials conducted by six independent labs, suggesting that the effects are robust and that DBIs should be considered for the prevention of other problems, such as smoking, substance abuse, HIV, and diabetes care

Predicting Weight Outcomes in Preadolescence: The Role of Toddlers? Self-regulation Skills and the Temperament Dimension of Pleasure

Objective To investigate the role of toddlers? self-regulation skills and temperament in predicting weight outcomes in preadolescence. Method Participants for this study included 195 children (114 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. At 2 years of age, participants participated in several laboratory tasks designed to assess their self-regulation abilities, including emotion regulation, sustained attention, and delay of gratification, while parents filled out a temperament questionnaire to assess toddlers? pleasure expression. Height and weight measures were collected when children were 4, 5, 7, and 10 years of age. Children also filled out a body image and eating questionnaire at the 10 year visit. Results Self-regulation skills in toddlers were associated with both BMI development, pediatric obesity, and body image/eating concerns. The temperament dimension of pleasure was also associated with BMI development and pediatric obesity but not body image/eating concerns. Conclusion Self-regulation difficulties across domains as well as temperament based pleasure in toddlers represented significant individual risk factors for the development of pediatric obesity eight years later. Early self-regulation difficulties also contributed to body image and eating concerns that typically accompanied overweight children. The mechanisms by which early self-regulation skills and temperament based pleasure may contribute to the development of pediatric obesity and associated weight concerns are discussed